Control mast



H. C. CRAY.

CONTROL MAST.

APPLICATION FILED AUG. 1. 192x.

1,432,970. Patented Oct. 24, 1922.

ii 5f I j H Patented 0st. 24a 1922.

Fidtfiiilo HARRY G. CRAY,'OF AKRON, OHIO,

CONTROL MAST.

Application filed August 1, 1921.

for controlling the direction of flight of an aircraft, and more particularly to an improved means for transmitting the pull upon the control cables to the control surfaces of an aircraft.

In the conventional type of aircraft design, the control surface is attached by means ofhinges, and a single control mast or horn is attached on either side of and near the center of said control surface, the mast or horn being adapted to receive, at both ends, control wires. Taking for example a control surface with a hinge at either end and a single control mast at the center of said surface, it will be readily seen that an excessive strain would result in a damaging effect upon the mast; produce a tendency of the control surfaces, when in certain position, to lock against movement; and also cause the control surfaces to warp near or at their ends. under the efiect of said strain. In order to obviate these difficulties, it is proposed to provide a control mast which will be capable of being attached at each hinge. either surrounding same, as in the case of a single hinge, or intermediate same, as in the case of a double hinge, said mast also being adapted to be applied to any type of aircraft on any control surface, such as the rudder. aileron, or elevator. The proposed combined design of hinge and mast will cause the pull of the control cables, attached to said mast, to act directly on the center of the hinge bearing. In this manner the ordinary slight bending of the control surface spar or tube due to the above men tioned pull, is eliminated, and produces an exceedingly easily operable control.

With the foregoing and other objects in view, which will appear as the descriptionproceeds, the invention resides in the combination of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed may be made within the scope of what is claimed, without departing from the spirit of the invention, the specific embodi- Serial No. 488,992.

ments of which are illustrated in the attached drawings, in which, V

Figure 1 is a front elevation view showing the manner in which the control mast is at tached to the tube at the control surface hinge of the single type;

Figure 2 is a view taken at a right angle .to Figure 1, showing additionally the attachment of the mast to the spar;

Figure 3 is a plan view showing a double hinge;

Figure 4 is a detail view of the control mast alone unattached.

As shown in Figure 1, 13 represents a control surface tube around which is mounted a semi-circular plate 20 secured by bolts 17 and nuts 15 and 16. Integral with said semi-circular plate 20 are the mast arms 1. At a point 18 is an opening for a single hinge strap 2. In this construction the pull upon the control cables will be transferred to each control mast arm at each hinge member. This arrangement is desirable in small type aircraft where the strain is usually comparatively small. However, for use in larger aircraft where the above mentioned strain is greater, a double hinge is used and the mast construction is arranged between the two straps of the double hinge, as shown in Figure 3.

Referring more particularly to Figure 2, 9 represents a spar and a control surface tube. The spar 9 is provided with a recess 19 to receive a corresponding projection of a bearing member 3, which has its opposite Face cut away to form a concaved bearing face 22 and has its outer sides bevelled at 21. in order to retain the bearing 3 against the spar 9, a plate 7 is arranged on one side of spar 9 and a casting 1 is fitted on the bevelled outer surface 21 of the bearing 3. A hearing strap 2 passes around the rear of the tube 13. Passing through the plate members 7, 4t and 2 are bolts 8 provided with nuts 10 at one end and 11 at the other, for the purpose of retaining the plates in the desired. position, plates 4L and 2 being provided with shims or spacing members 6.

The control. surface tube 13 is provided with a yoke block 14, held in place by the plate 20, and bolts 17, retained by nuts 15 and 16, and passing through both plate 20 and block 14. Extending from block 14; are arms 1. having apertures 1 and 1 at either extremities to receive control wires. Attached to said block lgt is a control surface or movable stabilizer 12 which may either be a rudder, elevator or aileron. By exerting a pull on one control wire the control surface moves in that corresponding direction, the other control wire, upon opera tion, pulling the surface 12 in the other direction.

The structure shown in Fig. 3 employs twobearing straps 2 which lie on opposite sides of the plate 20, instead of the single central strap 2 of Fig. 2. This makes a stronger hinge connection for larger aircraft stabilizers, the tube 13 being embraced at two points by the straps 2, as shown. The straps 2 are oined-together by aconne'cting portion 23.

Instead of'connecting the masts 1 to a hub plate 20, as in Figs. 1, 2, and 3, the masts 1 (see 4) may be provided with flanges 24- secured by any suitable fastening means to the opposite sides of the stabilizer 12. The bearing member 3 and strap 2 encircle the tube 13, and the spar 9 is clamped between the members 3 and i.

It willbe readily seen that, by this construction, a control surface operating means is provided which will be operable with the greatest ease, eliminate to a great degree the strain upon the mast and the control surface, and lessen the danger of the control surfaces becoming accidentally locked against desired movement.

Having described my invention, I claim,

1. An aircraft stabilizer having a control tube coincident with its axis of movement, a U-shaped hub plate embracing said tube and the adjacent portion of the stabilizer, masts extending from said hub plate, and a supporting bearing for said tube embodying a strap which passes around the tube and. abuts the hub plate.

In an operating means for-aircraft control surfaces, a wing spar provided on one face with a groove to receive a bearing member, said bearing member beingprovided with bevelled sides to receive a retaining casting, retaining bolts connecting said cas ing and a plate on the opposite face of said spar, a yoke block mounted on said tube and carrying a control surface, and a plate mountedonthe opposite side of said tube, said plate bearing against said bearing member and-connected to said yoke block, arms extending from said plate, said arms being adapted to receive, at their outer extremities, control wires for operating said control surface.

signature.

HARRY e. GRAY. 

